Waterproof rotation mechanism and radar antenna device

Abstract

A waterproof rotary mechanism is provided. The mechanism includes a stationary part, a rotary part having a receiver arranged above the stationary part and rotatably supported by the stationary part on a vertical axis as a rotating center thereof, and a clearance forming part fixed to the stationary part and arranged between the stationary part and the receiver. A clearance for suppressing water from entering therein and is formed between the receiver and the clearance forming part.

What is claimed is: 
     
         1 . A waterproof rotary mechanism, comprising:
 a stationary part;   a rotary part having a receiver arranged above the stationary part, and rotatably supported by the stationary part on a vertical axis as a rotating center thereof; and   a clearance forming part fixed to the stationary part and arranged between the stationary part and the receiver, wherein a clearance for suppressing water from entering therein is formed between the receiver and the clearance forming part.   
     
     
         2 . The mechanism of  claim 1 , wherein the clearance forming part has a first inclining portion, the first inclining portion being formed to extend downwardly toward outside in a radial direction of the rotary part. 
     
     
         3 . The mechanism of  claim 1 , wherein the stationary part has a second inclining portion arranged below the clearance forming part, the second inclining portion being formed to extend downwardly toward outside in a radial direction of the rotary part. 
     
     
         4 . The mechanism of  claim 1 , wherein the clearance formed between the receiver and the clearance forming part extends in the vertical direction. 
     
     
         5 . The mechanism of  claim 4 , wherein the receiver has a first opposing portion, while the clearance forming part has a second opposing portion, and
 wherein the second opposing portion is arranged in parallel with the first opposing portion, forms the clearance in conjunction with the first opposing portion, and is arranged inward of the first opposing portion in a radial direction of the rotary part.   
     
     
         6 . The mechanism of  claim 1 , wherein the clearance formed between the receiver and the clearance forming part includes a plurality of clearances for suppressing water from entering therein. 
     
     
         7 . The mechanism of  claim 6 , wherein the plurality of clearances are formed in shapes of concentric circles centered at the vertical axis, respectively. 
     
     
         8 . The mechanism of  claim 1 , further comprising:
 an oil holder arranged between the clearance forming part and the receiver and supported by the stationary part, and for holding oil therein; and   a contact part fixed to the receiver and contacting the oil in the oil holder.   
     
     
         9 . The mechanism of  claim 8 , wherein a part of the contact part is arranged within the space in the oil holder; and
 wherein a labyrinth is formed between the oil holder and the contact part.   
     
     
         10 . The mechanism of  claim 1 , further comprising a drainage path formed by using the clearance forming part and the stationary part, and for discharging the water. 
     
     
         11 . The mechanism of  claim 10 , wherein the drainage path extends outwardly in a radial direction of the rotary part to be open to outside the waterproof rotation mechanism, and has a section having wider width in the vertical direction, toward inside in the radial direction of the rotary part. 
     
     
         12 . A radar antenna device, comprising:
 the waterproof rotation mechanism of  claim 1 ; and   an antenna fixed to the receiver and rotatable on the vertical axis as a rotating center thereof.